The cause was liver cancer, said his assistant, Dena Levitin. Mr. Wilson's cancer was diagnosed in the summer, and his illness was made public last month.

''Radio Golf,'' the last of the 10 plays that constitute Mr. Wilson's majestic theatrical cycle, opened at the Yale Repertory Theater last spring and has subsequently been produced in Los Angeles. It was the concluding chapter in a spellbinding story that began more than two decades ago, when Mr. Wilson's play ''Ma Rainey's Black Bottom'' had its debut at the same theater, in 1984, and announced the arrival of a major talent, fully matured.

Reviewing the play's Broadway premiere for The New York Times, Frank Rich wrote that in ''Ma Rainey,'' Mr. Wilson ''sends the entire history of black America crashing down upon our heads.''

''This play is a searing inside account of what white racism does to its victims,'' Mr. Rich continued, ''and it floats on the same authentic artistry as the blues music it celebrates.''

In the years since ''Ma Rainey'' appeared, Mr. Wilson collected innumerable accolades for his work, including seven New York Drama Critics' Circle awards, a Tony Award, for 1987's ''Fences,'' and two Pulitzer Prizes, for ''Fences'' and ''The Piano Lesson,'' from 1990.

''He was a giant figure in American theater,'' the playwright Tony Kushner said yesterday. ''Heroic is not a word one uses often without embarrassment to describe a writer or playwright, but the diligence and ferocity of effort behind the creation of his body of work is really an epic story.

''The playwright's voice in American culture is perceived as having been usurped by television and film, but he reasserted the power of drama to describe large social forces, to explore the meaning of an entire people's experience in American history. For all the magic in his plays, he was writing in the grand tradition of Eugene O'Neill and Arthur Miller, the politically engaged, direct, social realist drama. He was reclaiming ground for the theater that most people thought had been abandoned.''

To honor his achievements, Broadway's Virginia Theater is to be renamed the August Wilson Theater. The new marquee is to be unveiled Oct. 17.

With the exceptions of ''Radio Golf'' and ''Jitney,'' a play first produced in St. Paul in 1981 and reworked and presented Off Broadway in 2000, all of the plays in the cycle were ultimately seen on Broadway, the sometimes treacherous but all-important commercial marketplace for American theater. Although some were not financial successes there, ''Fences,'' which starred James Earl Jones, set a record for a nonmusical Broadway production when it grossed $11 million in a single year, and ran for 525 performances. Together, Mr. Wilson's plays logged nearly 1,800 performances on Broadway in a little more than two decades, and they have been seen in more than 2,000 separate productions, amateur and professional.

Each of the plays in the cycle was set in a different decade of the 20th century, and all but ''Ma Rainey'' took place in the impoverished but vibrant African-American Hill District of Pittsburgh, where Mr. Wilson was born. In 1978, before he had become a successful writer, Mr. Wilson moved to St. Paul, and in 1994 he settled in Seattle, where he died. But his spiritual home remained the rough streets of the Hill District, where as a young man he sat in thrall to the voices of African-American working men and women. Years later, he would discern in their stories, their jokes and their squabbles the raw material for an art that would celebrate the sustaining richness of the black American experience, bruising as it often was.

In his work, Mr. Wilson depicted the struggles of black Americans with uncommon lyrical richness, theatrical density and emotional heft, in plays that gave vivid voices to people on the frayed margins of life: cabdrivers and maids, garbagemen and side men and petty criminals. In bringing to the popular American stage the gritty specifics of the lives of his poor, trouble-plagued and sometimes powerfully embittered black characters, Mr. Wilson also described universal truths about the struggle for dignity, love, security and happiness in the face of often overwhelming obstacles.

In dialogue that married the complexity of jazz to the emotional power of the blues, he also argued eloquently for the importance of black Americans' honoring the pain and passion in their history, not burying it to smooth the road to assimilation. For Mr. Wilson, it was imperative for black Americans to draw upon the moral and spiritual nobility of their ancestors' struggles to inspire their own ongoing fight against the legacies of white racism.

In an article about his cycle for The Times in 2000, Mr. Wilson wrote, ''I wanted to place this culture onstage in all its richness and fullness and to demonstrate its ability to sustain us in all areas of human life and endeavor and through profound moments of our history in which the larger society has thought less of us than we have thought of ourselves.''

Mr. Wilson did not establish the chronological framework of his cycle until after the work had begun, and he skipped around in time. Although ''Radio Golf,'' the last play to be written, was set in the 1990's, ''Gem of the Ocean,'' which immediately preceded it in production (it came to Broadway in the fall of 2004), was set in the first decade of the 20th century.

His first success, ''Ma Rainey,'' which took place in a Chicago recording studio in 1927, depicted the turbulent relationship between a rich but angry blues singer and a brilliant trumpet player who also wants to succeed in the white-dominated world of commercial music. From there Mr. Wilson turned to the 1950's, with ''Fences,'' his most popular play, about a garbageman and former baseball player in the Negro leagues who clashes with his son over the boy's intention to pursue a career in sports. His next play, ''Joe Turner's Come and Gone,'' considered by many to be the finest of his works, was a quasi-mystical drama set in a boardinghouse in 1911. It told of a man newly freed from illegal servitude searching to find the woman who abandoned him.

The other plays in Mr. Wilson's theatrical opus are ''The Piano Lesson,'' set in 1936, in which a brother and sister argue over the fate of the piano that symbolizes the family's anguished past history; ''Two Trains Running,'' concerning an ex-con re-ordering his life in 1969; ''Seven Guitars,'' about a blues musician on the brink of a career breakthrough in 1948; ''Jitney,'' a collage of the everyday doings at a gypsy cab company in 1977; and ''King Hedley II,'' in which another troubled ex-con searches for redemption as the Hill District crumbles under the onslaught of Reaganomics in 1985.

As the cycle developed, Mr. Wilson knit the plays together through overlapping themes and characters. Many of the primary conflicts concern the dueling prerogatives of characters poised between the traumatizing past and the uncertain future. The central character in ''Radio Golf'' is the grandson of a character in ''Gem of the Ocean.'' The guiding spiritof the cycle came to be Aunt Esther, a woman said to have lived for more than three centuries, who was referred to in several plays and who appeared at last in ''Gem.'' She embodied the continuity of spiritual and moral values that Mr. Wilson felt was crucial to the black experience, uniting the descendants of slaves to their African ancestors.

A Fruitful Partnership
 

Mr. Wilson's career was closely linked with that of Lloyd Richards, who became the first black director to work on Broadway when he staged the first play written by a black woman to be produced on Broadway, Lorraine Hansberry's ''Raisin in the Sun,'' in 1959. Ms. Hansberry's warmhearted but clear-eyed play about the struggles of a black family to move up the economic ladder in Chicago shares with Mr. Wilson's work a focus on the daily lives of black Americans, relegating the oppressions of white culture to the background.

Mr. Richards, the dean of the Yale School of Drama and the artistic director of Yale Repertory Theater from 1979 to 1991, was also the head of the Eugene O'Neill Playwrights Conference in Connecticut when Mr. Wilson submitted ''Ma Rainey'' to the program. (''Jitney,'' begun in 1979, had been submitted and rejected twice.) When it was accepted, Mr. Richards helped refine the work of the then-unknown writer and first produced and directed it at Yale Rep, where its success instantly established Mr. Wilson as an American playwright of singular talent, perhaps the greatest American stage poet since Tennessee Williams.

Mr. Richards would help shape and direct the next five plays in Mr. Wilson's cycle, ending with ''Seven Guitars,'' which arrived on Broadway in 1996. Each play was refined through a series of productions at Yale and other regional theaters before moving to New York. (Most grew significantly shorter along the way: Mr. Wilson's work was most often criticized for excessive length and sometimes belaboring its ideas. In a celebratory review Mr. Rich wrote when ''Joe Turner'' opened on Broadway, he nevertheless noted, ''As usual with Mr. Wilson, the play overstates its thematic exposition in an overlong first act.'')

This formula replicated in a noncommercial arena the tryout circuit that had once been commonplace for plays aiming for Broadway, a method of development that ran aground as the costs of theater skyrocketed. The process, which also involved Mr. Wilson's longtime producer, Benjamin Mordecai, the managing director of Yale Rep during much of Mr. Richards's tenure, was important in defining a healthy and mutually beneficial relationship between the country's not-for-profit regional theaters and its Broadway-centered commercial establishment. (Mr. Mordecai, who was involved with all of Mr. Wilson's plays in one capacity or another, died earlier this year.) More significantly, the collaboration between Mr. Richards and Mr. Wilson was the most artistically fruitful in American theatrical history since Elia Kazan's association with Arthur Miller and Williams.

An Atypical Education
 

Mr. Wilson was born Frederick August Kittel on April 27, 1945, in Pittsburgh. He was named for his father, a white German immigrant who worked as a baker, drank too much and had a fiery temperament his son would inherit. He was mostly an absence in Mr. Wilson's childhood, and it was his African-American mother, Daisy Wilson, who instilled in her six children a strong sense of pride and a limited tolerance for injustice. (She once turned down a washing machine she had won in a contest when the company sponsoring the event tried to fob off a secondhand item on her.) Mr. Wilson legally adopted her last name when he set out to become a writer.

Eventually Mrs. Wilson divorced Mr. Wilson's father and remarried, and the family moved to a largely white suburb. As the only black student in his class at a Roman Catholic high school, Mr. Wilson gained an awareness of the grinding ugliness of racism that would inform his work. ''There was a note on my desk every single day,'' he told The New Yorker in 2001. ''It said, 'Go home, nigger.''' Mr. Wilson attended two more schools but gave up on formal education when a teacher accused him of plagiarizing a paper on Napoleon. At 15, he chose to continue -- but essentially to begin -- his education on his own, spending his days at the local library absorbing books by the dozen.

Mr. Wilson acquired an equally valuable education outside the library walls, hanging out and listening to the Hill District denizens pass the time on stoops, in coffee shops and at Pat's Place, a local cigar store. Eventually the voices he absorbed while hanging loose with retirees and sharpies in his 20's would re-emerge in his plays, sometimes with little artistic tampering.

Mr. Wilson acquired his first typewriter with $20 he had earned writing a term paper for one of his sisters at college. But he preferred to write in public places like bars and restaurants and had a particular affinity for composing on cocktail napkins. Only when he settled into his career as a playwright did he become comfortable writing at home, in longhand on yellow notepads.

By the time he was 20, Mr. Wilson had decided he was a poet. He submitted poems to Harper's and other magazines while supporting himself with odd jobs, and began dressing in a style that raised eyebrows among his peers. While most of the young men of the time were dressing down, Mr. Wilson was always meticulously turned out in jackets, ties and white shirts selected from thrift shops. Later he would be known for his trademark porter's cap.

Inspired by the Black Power movement then gaining momentum, Mr. Wilson and a group of fellow poets founded a theater workshop and an art gallery, and in 1968 Mr. Wilson and his friend Rob Penny founded the Black Horizons on the Hill Theater. Mr. Wilson was the director and sometimes an actor, too, although he had no experience, and learned about directing by checking a how-to manual out of the library. The company was without a performance space and staged shows in the auditoriums of local elementary schools. Tickets were sold, for 50 cents a pop, by chatting up people on the streets right before a performance.

But Mr. Wilson's aspirations as an author were still being channeled into poetry; after an abortive effort to write a play for his theater, he set aside playwriting for almost a decade. He came home to drama almost by happenstance. Mr. Wilson moved to St. Paul in 1978 and started working at the Science Museum of Minnesota. His task: adapting Native American folk tales into children's plays.

Homesick for the Hill District and growing more comfortable with the playwriting process, he started channeling the Hill voices haunting his memories as a way of keeping the connection alive. ''Jitney,'' begun in 1979, was the result. It was produced in Pittsburgh in 1982, the same year that ''Ma Rainey'' was accepted at the O'Neill Center. (Mr. Wilson's first professional production was of a prior play adapted from a series of his poems, ''Black Bart and the Sacred Hills,'' staged by St. Paul's Penumbra Theater.)

In a 1999 interview in The Paris Review, Mr. Wilson cited his major influences as being the ''four B's'': the blues was the ''primary'' influence, followed by Jorge Luis Borges, the playwright Amiri Baraka and the painter Romare Bearden. He analyzed the elements each contributed to his art: ''From Borges, those wonderful gaucho stories from which I learned that you can be specific as to a time and place and culture and still have the work resonate with the universal themes of love, honor, duty, betrayal, etc. From Amiri Baraka, I learned that all art is political, although I don't write political plays. From Romare Bearden I learned that the fullness and richness of everyday life can be rendered without compromise or sentimentality.'' He added two more B's, both African-American writers, to the list: the playwright Ed Bullins and James Baldwin.

Although his plays achieved their success in the white-dominated theater world, Mr. Wilson remained devoted to the alternative culture of black Americans and mourned its gradual decline as the black middle class grew and adopted the values of its white counterpart. He once lamented that at convocation ceremonies at black universities, the music would be Bach, not gospel.

When a Hollywood studio optioned ''Fences,'' Mr. Wilson caused a ruckus by insisting on a black director. In a 1990 article published in Spin magazine and later excerpted in The Times, he said, ''I am not carrying a banner for black directors. I think they should carry their own. I am not trying to get work for black directors. I am trying to get the film of my play made in the best possible way. I declined a white director not on the basis of race but on the basis of culture. White directors are not qualified for the job. The job requires someone who shares the specifics of the culture of black Americans.'' (The film was not made.)

He was a firm believer in the importance of maintaining a robust black theater movement, a viewpoint that also inspired a public controversy when Mr. Wilson clashed with the prominent theater critic and arts administrator Robert Brustein in a series of exchanges in the pages of American Theater magazine and The New Republic, and later in a formal debate between the two staged at Manhattan's Town Hall in 1997, moderated by Anna Deavere Smith.

The contretemps began when Mr. Wilson delivered a keynote address to a national theater conference in which he lamented that among the more than 60 members of the League of Regional Theaters, only one was dedicated to the work of African-Americans. He also denounced as absurd the idea of colorblind casting, asserting that an all-black ''Death of a Salesman'' was irrelevant because the play was ''conceived for white actors as an investigation of the specifics of white culture.'' Mr. Brustein referred to Mr. Wilson's call for an independent black theater movement as ''self-segregation.''

At the sold-out debate at Town Hall the friendly antagonists essentially restated their positions publicly. ''Never is it suggested that playwrights like David Mamet or Terrence McNally are limiting themselves to whiteness,'' Mr. Wilson said. ''The idea that we are trying to escape from the ghetto of black culture is insulting.''

A Legacy of Stars
 

Mr. Wilson was dedicated to writing for the theater, and resisted many offers from Hollywood. (His only concession: adapting ''The Piano Lesson'' for television.) He didn't even see any movies for a stretch of 10 years.

But the list of well-known television and film actors who first came to prominence in one of Mr. Wilson's plays is lengthy. Charles S. Dutton scored his first success as the trumpeter Levee in the original production of ''Ma Rainey's Black Bottom,'' a role he reprised nearly 20 years later when the play was revived on Broadway in 2003, with Whoopi Goldberg in the title role. S. Epatha Merkerson, now known as Lt. Anita Van Buren on ''Law & Order,'' appeared opposite Mr. Dutton in ''The Piano Lesson'' on Broadway.

Other notable actors who appeared in one or more of Mr. Wilson's plays include Angela Bassett, Roscoe Lee Browne, Phylicia Rashad, Courtney B. Vance, Laurence Fishburne, Lisa Gay Hamilton, Keith David, Viola Davis, Delroy Lindo, Ruben Santiago-Hudson, Leslie Uggams and Brian Stokes Mitchell.

Mr. Wilson's first two marriages, to Brenda Burton and Judy Oliver, ended in divorce. He is survived by his wife, Constanza Romero, a Colombian-born costume designer he met when she worked on ''The Piano Lesson''; and two daughters, Sakina Ansari (from his first marriage) and Azula Carmen Wilson (from his third). He is also survived by his siblings Freda Ellis, Linda Jean Kittel, Richard Kittel, Donna Conley and Edwin Kittel.

Mr. Wilson did not write plays with specific political agendas, but he did believe art could subtly effect social change. And while his essential aim was to evoke and ennoble the collective African-American experience, he also believed his work could help rewrite some of those rules.

''I think my plays offer (white Americans) a different way to look at black Americans,'' he told The Paris Review. ''For instance, in 'Fences' they see a garbageman, a person they don't really look at, although they see a garbageman every day. By looking at Troy's life, white people find out that the content of this black garbageman's life is affected by the same things -- love, honor, beauty, betrayal, duty. Recognizing that these things are as much part of his life as theirs can affect how they think about and deal with black people in their lives.''

In describing his own work, Mr. Wilson could be analytical or offhand. A soft-spoken man whose affability masked a sometimes short temper, he was a connoisseur of the art of storytelling offstage and on. Here's the story behind all his characters' stories, in his own words: ''I once wrote a short story called 'The Best Blues Singer in the World' and it went like this: 'The streets that Balboa walked were his own private ocean, and Balboa was drowning.' End of story. That says it all. Nothing else to say. I've been rewriting that same story over and over again. All my plays are rewriting that same story. I'm not sure what it means, other than life is hard.''
 

Correction: October 6, 2005, Thursday The obituary of the playwright August Wilson on Monday referred incorrectly at one point to the premiere of his play ''Jitney.'' It was at the Allegheny Repertory Theater in Pittsburgh in 1982, not in St. Paul in 1981. The article also omitted a survivor; she is Mr. Wilson's fourth sister, Barbara Jean Wilson.